I have the one from Murry's, and it is a must for solo sailing. I loop one end of the rope around the mast pin before raising the mast. Make sure you don't use too much line, otherwise the pulley system will be caught on the hull. I've tied the bag straps to the front trampoline in front of the mast. It gets strapped there until I need it. In this picture you can see the straps on the trampoline and the rope under the mast, but the bag and pulley are unraveled in on the trampoline.

To use it, simply unstrap it and throw it over the hull - between the hull and the wings. I've found it helpful to have most of the bag and line wrapped securely in rope, separate from the straps, otherwise when you throw it, it's a mess and doesn't go where you want. Then I go around to the other side and get it ready to go. Usually I am drifting, so I open the bag to naturally fill up with the flow of water. Then hoist it up. The weight of the water alone won't right it, but get between it and the boat and push it outward with your legs, and it works like a charm. In heavy winds, you might have to position the boat a bit, because the double trampoline catches so much wind it can counteract a lot of leverage.

Plunk. You're good to go. The bag even anchors the boat a bit while you get back on.